Inferring aliasing and encapsulation properties for java

There are many proposals for language techniques to control aliasing and encapsulation in object oriented programs, typically based on notions of object ownership and pointer uniqueness. Most of these systems require extensive manual annotations, and thus there is little experience with these properties in large, existing Java code bases. To remedy this situation, we present Uno, a novel static analysis for automatically inferring ownership, uniqueness, and other aliasing and encapsulation properties in Java. Our analysis requires no annotations, and combines an intraprocedural points-to analysis with an interprocedural, demand-driven predicate resolution algorithm. We have applied Uno to a variety of Java applications and found that some aliasing properties, such as temporarily lending a reference to a method, are common, while others, in particular field and argument ownership, are relatively uncommon. As a result, we believe that Uno can be a valuable tool for discovering and understanding aliasing and encapsulation in Java programs.